[PATCH v3 2/6] clocksource: add Marvell Orion SoC timer
Sebastian Hesselbarth
sebastian.hesselbarth at gmail.com
Fri Jun 7 02:27:10 EST 2013
This patch add a DT enabled driver for timers found on Marvell Orion SoCs
(Kirkwood, Dove, Orion5x, and Discovery Innovation). It installs a free-
running clocksource on timer0 and a clockevent source on timer1.
Corresponding device tree documentation is also added.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
---
Cc: Grant Likely <grant.likely at linaro.org>
Cc: Rob Herring <rob.herring at calxeda.com>
Cc: Rob Landley <rob at landley.net>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: John Stultz <john.stultz at linaro.org>
Cc: Russell King <linux at arm.linux.org.uk>
Cc: Jason Cooper <jason at lakedaemon.net>
Cc: Andrew Lunn <andrew at lunn.ch>
Cc: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Cc: Gregory Clement <gregory.clement at free-electrons.com>
Cc: devicetree-discuss at lists.ozlabs.org
Cc: linux-doc at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
---
.../bindings/timer/marvell,orion-timer.txt | 17 +++
drivers/clocksource/Kconfig | 5 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/time-orion.c | 143 ++++++++++++++++++++
4 files changed, 166 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/timer/marvell,orion-timer.txt
create mode 100644 drivers/clocksource/time-orion.c
diff --git a/Documentation/devicetree/bindings/timer/marvell,orion-timer.txt b/Documentation/devicetree/bindings/timer/marvell,orion-timer.txt
new file mode 100644
index 0000000..62bb826
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/marvell,orion-timer.txt
@@ -0,0 +1,17 @@
+Marvell Orion SoC timer
+
+Required properties:
+- compatible: shall be "marvell,orion-timer"
+- reg: base address of the timer register starting with TIMERS CONTROL register
+- interrupt-parent: phandle of the bridge interrupt controller
+- interrupts: should contain the interrupts for Timer0 and Timer1
+- clocks: phandle of timer reference clock (tclk)
+
+Example:
+ timer: timer {
+ compatible = "marvell,orion-timer";
+ reg = <0x20300 0x20>;
+ interrupt-parent = <&bridge_intc>;
+ interrupts = <1>, <2>;
+ clocks = <&core_clk 0>;
+ };
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index f151c6c..2404869 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -25,6 +25,11 @@ config DW_APB_TIMER_OF
config ARMADA_370_XP_TIMER
bool
+config ORION_TIMER
+ select CLKSRC_OF
+ select CLKSRC_MMIO
+ bool
+
config SUN4I_TIMER
bool
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 8d979c7..d1e8d68 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o
obj-$(CONFIG_CLKSRC_NOMADIK_MTU) += nomadik-mtu.o
obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o
obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o
+obj-$(CONFIG_ORION_TIMER) += time-orion.o
obj-$(CONFIG_ARCH_BCM2835) += bcm2835_timer.o
obj-$(CONFIG_ARCH_MARCO) += timer-marco.o
obj-$(CONFIG_ARCH_MXS) += mxs_timer.o
diff --git a/drivers/clocksource/time-orion.c b/drivers/clocksource/time-orion.c
new file mode 100644
index 0000000..4ecb2f8
--- /dev/null
+++ b/drivers/clocksource/time-orion.c
@@ -0,0 +1,143 @@
+/*
+ * Marvell Orion SoC timer handling.
+ *
+ * Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * Timer 0 is used as free-running clocksource, while timer 1 is
+ * used as clock_event_device.
+ */
+
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <asm/sched_clock.h>
+
+#define TIMER_CTRL 0x00
+#define TIMER0_EN BIT(0)
+#define TIMER0_RELOAD_EN BIT(1)
+#define TIMER1_EN BIT(2)
+#define TIMER1_RELOAD_EN BIT(3)
+#define TIMER0_RELOAD 0x10
+#define TIMER0_VAL 0x14
+#define TIMER1_RELOAD 0x18
+#define TIMER1_VAL 0x1c
+
+#define ORION_ONESHOT_MIN 1
+#define ORION_ONESHOT_MAX 0xfffffffe
+
+static void __iomem *timer_base;
+
+/*
+ * Free-running clocksource handling.
+ */
+static u32 notrace orion_read_sched_clock(void)
+{
+ return ~readl(timer_base + TIMER0_VAL);
+}
+
+/*
+ * Clockevent handling.
+ */
+static u32 ticks_per_jiffy;
+
+static int orion_clkevt_next_event(unsigned long delta,
+ struct clock_event_device *dev)
+{
+ u32 u;
+
+ /* setup and enable one-shot timer */
+ writel(delta, timer_base + TIMER1_VAL);
+ u = readl(timer_base + TIMER_CTRL) & ~TIMER1_RELOAD_EN;
+ writel(u | TIMER1_EN, timer_base + TIMER_CTRL);
+
+ return 0;
+}
+
+static void orion_clkevt_mode(enum clock_event_mode mode,
+ struct clock_event_device *dev)
+{
+ u32 u;
+
+ if (mode == CLOCK_EVT_MODE_PERIODIC) {
+ /* setup and enable periodic timer at 1/HZ intervals */
+ writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD);
+ writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL);
+ u = readl(timer_base + TIMER_CTRL);
+ writel(u | TIMER1_EN | TIMER1_RELOAD_EN,
+ timer_base + TIMER_CTRL);
+ } else {
+ /* disable timer */
+ u = readl(timer_base + TIMER_CTRL) & ~TIMER1_EN;
+ writel(u, timer_base + TIMER_CTRL);
+ }
+}
+
+static struct clock_event_device orion_clkevt = {
+ .name = "orion_event",
+ .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+ .shift = 32,
+ .rating = 300,
+ .set_next_event = orion_clkevt_next_event,
+ .set_mode = orion_clkevt_mode,
+};
+
+static irqreturn_t orion_clkevt_irq_handler(int irq, void *dev_id)
+{
+ orion_clkevt.event_handler(&orion_clkevt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction orion_clkevt_irq = {
+ .name = "orion_event",
+ .flags = IRQF_DISABLED | IRQF_TIMER,
+ .handler = orion_clkevt_irq_handler,
+};
+
+static void __init orion_timer_init(struct device_node *np)
+{
+ struct clk *clk;
+ int irq;
+
+ /* timer registers are shared with watchdog timer */
+ timer_base = of_iomap(np, 0);
+ if (!timer_base)
+ panic("%s: unable to map resource\n", np->name);
+
+ clk = of_clk_get(np, 0);
+ if (IS_ERR(clk))
+ panic("%s: unable to get clk\n", np->name);
+ clk_prepare_enable(clk);
+
+ /* we are only interested in timer1 irq */
+ irq = irq_of_parse_and_map(np, 1);
+ if (irq <= 0)
+ panic("%s: unable to parse timer1 irq\n", np->name);
+
+ /* setup timer0 as free-running clocksource */
+ writel(~0, timer_base + TIMER0_VAL);
+ writel(~0, timer_base + TIMER0_RELOAD);
+ writel(readl(timer_base + TIMER_CTRL) | TIMER0_EN | TIMER0_RELOAD_EN,
+ timer_base + TIMER_CTRL);
+ clocksource_mmio_init(timer_base + TIMER0_VAL, "orion_clocksource",
+ clk_get_rate(clk), 300, 32,
+ clocksource_mmio_readl_down);
+ setup_sched_clock(orion_read_sched_clock, 32, clk_get_rate(clk));
+
+ /* setup timer1 as clockevent timer */
+ if (setup_irq(irq, &orion_clkevt_irq))
+ panic("%s: unable to setup irq\n", np->name);
+
+ ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ;
+ orion_clkevt.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&orion_clkevt, clk_get_rate(clk),
+ ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
+}
+CLOCKSOURCE_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);
--
1.7.2.5
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